It is currently a general practice to prepare and distribute direct mails carrying information on goods and services meeting the tastes of a specific user group. To do this, efforts will have to be paid to gather information on personal tastes typically by means of questionnairs and analyse the obtained data in order to find out the individual tastes of the respondents.
However, the above described conventional method for finding out personal tastes is accompanied by a number of problems. One of such problems is the difficulty of preparing adequate qeustionnaires because they are more often than not rather subjective and the findings can be different among the analysers who analyse the obtained data. Then, it will not be possible to accurately find out personal tastes. Another problem accompanying the conventional method is that the entire project of preparing questionnairs, collecting them and analysing them is very labour intensive and time consuming.
Still another problem is that the personal data obtained from the collected questionnaris can, if partly, be leaked to the outside to infringe on privacy.